Connector plug



Nov. 26, 1940. Q Q sMlTH "2,223,231

CONNECTOR 'PLUG Filed Sept. 10, 1937 Figi.

Patented Nov. 26, 1940 UNITED STATES coNNac'ron PLUG Charles C. Smith,Stratford, Conn., assignmto -General Electric Company, a corporation ofNew York Application september 1o, 1937, serial No. 133,281

1 Claim.

The present invention relates to connector plugs such as are used oncord lsets for connecting heating devices and the like to a currentsource.

In the manufacture of electrical connector plugs for relatively smallcurrents, it is known to mold the contacts and adjacent portions of theconductor cord which is connected to the contacts in rubber, or thelike, to provide a nonbreakable plug and a strain relief for theconnections between the cord conductors and the contacts.

In the manufacture of connector plugs for larger electric currents, asin the case of atiron connector plugs, for example, this has not beenpossible because of the high temperature which the contacts may reachduring operation, temperatures of the order of 600 F. being met withsometimes.

One object of the present invention is to provide an improved plugstructure wherein the connections between the cord conductors and thecontacts are molded in rubber, or the like,`

to provide a strain relief and which avoids dif- 'lculties in so far asthe highl temperatures met with are concerned.

A further object of the invention is to provide a plug structure whereinthe cord is firmly anchored in the plug body so that any pull on the lcord is taken by the body of the plug.

A further object of the invention is to provide an improved constructionof plug contact which is simple to manufacture and to which theconductor is connected without'the use of screws.

Further objects and the advantages of the invention are pointed out inthe following speciiication.

In the drawing, Fig. 1 is a top View of a plug embodying the invention,a portion of the plug body being broken away; Fig. 2 is a top view of aconnector plug with the upper half of the plug body removed; Fig. 3 isa. longitudinal sectional view of the plug; Fig. 4 is a perspective Viewof one of the plug contacts, and Fig. 5 is a top view of the twocontacts with the strain relief member molded thereon. y

Referring tothe drawing, the plug comprises a vplug body or housingformed of two complementary halves 6 and 'l fastened together by asuitable means, such as rivets 8. The plug body is formed from asuitable molding compound, such as a phenolic condensation product orother resinous substance and a suitable filler, capable of withstandingthe temperatures met with. It may be formed from any of the moldingcompounds now in use for connector plugs of this type. The plug body isprovided with a longitudinally extending partition 9 which divides theinterior of the body into two longitudinally extending passages I andIl. The par- 5 titionwall 9 terminates short of the rear end of the plugbody and at this point the plug, body is enlarged somewhat to provide apocket I2. At the inner end of the pocket I2 are shoulders I3. Thelongitudinal wall 9 is formed preferably with 10 a part integral witheach of the plug bodyhalves, the line of demarkation between the partsbeing indicated at I4 in Fig. 3. In the rear end of the plug body isanopening I which communicates Y with the pocket I2. In the fron't wall ofthe l5 plug are openings I6 for the admission of contact posts orblades. f

Located in the passages I0 and Il are contacts I'I. Referringparticularly to Fig. 4, each contact comprises a clamping endI or socketI8 and 20 arelatively long shank I9 of relatively limitedcross-sectional area to the outer end of which the conductors'of theelectric cord are connected. The walls forming the socket are curvedoutwardlyas indicated at to provide for the 25 admission of contactparts or blades between lthem and each is provided. at its centralportionwith a struck out spring tongue 2l which grips a contact postinserted between them. The contact is formed preferably of two stripswhich are substantially alike except that onev strip is provided withthe relatively long extension I9 and the two strips are fastenedtogether by suitable means as` by riveting, as indicated at 22. Theouter end of the extension I9 has its walls 35 bent around to provide atapered pocket 23 for the reception of the end of an electric wire.

An electric cord 2t having two conductor wires 25 is indicated in thedrawing. The ends of the conductor wires arevconnected one to each ofthe contacts Ii. This may be done by inserting the end of the wire inthe tapered pocket 23 and fixing it in place by means of solder asindicated at 26; or after the wire is in place, the walls of the pocketmay be squeezed down around the 45 wire by the use of a suitable tool.After the two conductors have been connected to the two contacts, thetwo contacts are assembled in correct spaced relation to each other in asuitable x-v ture and a body 21 of suitable insulating mate- 50 rial,such as rubber or the like, is molded directly around the outer ends ofthe extensions I9, the ends of the conductors 2i, and the adjacentportion of the cord 2l. This serves to anchor the connections betweenthe conductors and contacts l in the insulating body 21 and also toprovide a strain relief for the connections. Body 21 is of a size andshape to it in pocket I2 and it will be clear that any pull on the cord24 will be taken by the body 21 engaging the wall of the pocket. Thebody 21 at its inner end' ts against the shoulders I3 and is heldagainst'the shoulders by the tapered walls of the pocket as indicated at29. Preferably the adjacent portion of the cord 24 has material moldedaround it for quite some length as indicated at 30,- thus providingprotection against sharp bending of the cord where it enters the body,also it is preferably provided Witha bead or ange 3l which engages theouter rear face of the. plug body. To hold the contacts fromlongitudinal movement in passages I and II, body halves 8 and 1 areprovided with abutments 32 with which `the innerl ends of tongues 2|engage. y

In use, as pointed out above, a connector plug of this type is subjectedoften to fairly high temperature, the contact sockets I8 reaching sometimes temperatures of the order' of 600 F. This `is a temperature higherthan rubber or similar by molded body 21, the two body members 6' and 1can be permanently fastened together by rivets.

This is of advantage in that the fastening tol0 gether can be done atlow cost, and being permanently fastened together, the plug cannot betampered with. The sockets I8 of theV contacts fit loosely in thepassages III and II so that they can float to a limited extent to permitof connecl tion to posts or contact blades which may be somewhat out ofalignment.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

A connector plug comprising a housing formed of an insulating materialcapable of withstanding relatively high temperatures and having twoyspaced longitudinally extending passages and a pocket With which therear ends of said passages communicate, contact sockets in the forwardends of said passages, said sockets being provided with elongatedShanksv of relatively limited cross-sectional area extending from thesocket through the passages to said pocket, an electric cord having itsconductors connected to the ends of said 3G Shanks and resilientinsulating material surrounding and embedding the ends of said Shanksand the connections of the conductors therewith and forming a body whichfits in said pocket and is held in position by said housing, saidinsulating material extending a distance back from said housing andsurrounding said cord to form a strain relief sleeve, said shanksdissipating the heat from said contacts incidentto connection of theplug to a heating appliance to protect said body of insulating materialfrom damage due to the effect of the heat. CHARLES C. S 1

Since the connec- 5 tion between the conductors andthe contactsism n apermanent one and protected from breakage"

